docs: update compatibility documentation

README.md

@@ -24,11 +24,11 @@ You're ready to browse the [Catalog](#Catalog).
 
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 ## Compatibility
-Starting with v4.2.0 we keep track of compatibility between this catalog and flux2. Other versions might work too as long as there are no breaking changes.
+We keep track of compatibility between this catalog and flux2. Other versions might work too as long as there are no breaking changes.
 | flux-k8s-stack version | flux2 version |
 | ---------------------- | ------------- |
-| v5   | v0.41.2 |
-| v4  | v0.41.2 |
+| >= v9 | v2.0.0  |
+| <= v8 | v0.41.2 |
 
 ---
 ## Catalog